Single failure must not put every store down

Target has managed to hook every cash register in every store to somewhere central.  Somewhere center broke yesterday and the day before, locking up every single cash register all over the country, forcing customers to stand in line for hours, or, just leave their purchases and go home. 
  This should not happen.  A Target store is large enough to afford the computers to be stand alone.  Target didn't  bother to do this, and it will cost them.  Certainly I will think twice before doing business with Target, lest I get stuck in line for hours, or have my account information broadcast to every hacker in the world. 
   Target's disastrous cash register setup has to be the work of ignorant Target suits.  No competent engineer would design a system like that.  Engineers understand that things break every so often, and that to tie every cash register in the company into a central point is a company wide failure just waiting to happen. 
   For that matter, cash registers used to work just fine before computers were even invented.  And we managed to use credit cards for decades before the automatic approval systems we use today were installed.  Target would do well to revive these antique ways of doing business.